Aspect ratio enhancement

ABSTRACT

An adaptive compensation system for aspect ratio conversion. Video information, intended for her first aspect ratio display, e.g. the standard NTSC aspect ratio, is processed to determine additional information that can enable that video to be displayed and fill a wider aspect ratio screen. The processing can be a calculation which calculates, for example, texture, color and/or brightness of the edge portions, and automatically calculates video information to match the texture, brightness or color. The processing can be a database lookup, which automatically looks up likely portions from a database. The processing can also be an adaptive determination of what vertical portions of the image can be stretched without affecting the viewability, and then an adaptive stretching of different portions by different amounts.

CROSS RELATED APPLICATIONS

The present application claims priority from provisional application No.60/587,732, filed Jul. 13, 2004, and from application No. 60/572,550,filed May 18, 2004, the disclosures of which are hereby incorporated byreference.

BACKGROUND

A ratio between the length and width of a video display unit screen isoften called the “aspect ratio”. Conventional aspect ratios forbroadcast NTSC video is a ratio of 4:3. However, modern televisions andvideo display units are often formed with an aspect ratio of 16:9 oreven wider. Certain video programs support this wider aspect ratio.However, a large number of legacy programs are still broadcast and/orotherwise available only in the ratio of 4:3.

In certain modern screens, displaying on only part of the screen cancause problems. Specifically, if one part of the screen is used morethan others, then that unused part of the screen may age differentlythan those other parts. In certain screens this can cause unevenbrightness, or other problems which make television viewing experienceless enjoyable.

Conversely, simply displaying the program on the screen and leavingblack bars or like on sides of the displayed program, may look bad.

Some televisions attempt to obviate his problem by allowing the user towiden the program. However, the program recorded at 4:3 ratio (1.25) isthen displayed at a 16.9 or other ratio (wider than 1.25). This makesthe objects look out of proportion and funny. This has often been foundto be acceptable.

SUMMARY

The present application teaches enhancing use of a video system and itsaspect ratio. More specifically, an aspect teaches techniques tofacilitate displaying video programs on a video screen which has adifferent aspect ratio than the ratio for the program was originallyintended.

One aspect describes a technique of allowing preparing video displaymaterial for a video screen, where the material was intended originallyfor display on a screen with one aspect ratio, and to be used on videoscreens of a different aspect ratio.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects will now be described with reference to theaccompanying drawings, wherein:

FIG. 1 shows a block diagram of the basic system;

FIG. 2 shows a flowchart of operations;

FIGS. 3A-3C show different ways of handling the blank areas in a videoscreen;

FIG. 4A-4D illustrate different interpretation techniques;

FIGS. 5A-5C illustrate separate data display techniques; and

FIGS. 6A-6C illustrate adaptive compensation of the images,

DETAILED DESCRIPTION

One aspect of the present application defines displaying a program whichhas different length and width characteristics than the video screenwhich will be displaying that program. This may be used with broadcastmedia, where the broadcast media is intended to include broadcasts ofany frequency, both real-time, and time-shifted, satellite programming,recorded video, as well as any programming over media other than theabove.

FIG. 1 shows a basic block diagram of the system. Video information 100,from whatever source, is provided to processor 110 which operates toprocess the video, to either change some aspect of the video, or make adetermination of other operations, if any, to take. The processed video120 is output to a video screen 130 which is shown here as a wide screensystem. The embodiment given herein assumes that the video resolutionsof 4:3 being displayed on a screen of 16 by 9 aspect ratio. However, itshould be understood that any conversion between any two aspect ratiosor pixel ratios is alternatively possible.

The video processing element 110 can be a dedicated microprocessor, orcan be some kind of hardware processor, or can be dedicated circuitrywhich carries out the functions described herein. FIG. 2 shows a basicflowchart which is followed by processing circuit 110. At 200, theprocessing circuit determines if the video source is already widescreen.That is, 200 detects whether the video source coming in is already inthe proper format to fit on the wide screen 130. If so, the video sourcepasses the video to the display at 205 without modification.

If not, the processor 110 processes the video at 210. As shown in FIG.2, three basic kinds of processing are carried out. In the first basickind of processing at 215, the video is simply moved on the screen, andoperations are taken to avoid screen burn in. This may be considered themost rudimentary process, and probably the least desirable from theuser's point of view. 220 is an alternative which can be carried out,which calculates and/or compensates for overall brightness. This can bedone in conjunction with the other embodiments. The calculation andcompensation basically keeps a record of the number of times that eacharea on the screen has received specified amounts of brightness.Compensation is then carried out to attempt to render the brightness inother portions in a similar way to avoid screen burn in.

230 shows a routine for correlate/interpolate/enhance of the videoinformation. In this embodiment, electronic techniques are carried outto form additional portions for the video content to be displayed toform additional parts of the video.

These techniques are described in further detail herein.

FIG. 3A shows a basic concept of the move routine 215. Basically, thecontent 300 to be displayed is shown within the outer perimeter 302,leaving blank areas 304, 305. The video portion is moved cyclically backand forth to cycle the location on the screen that contains the blankareas, that is, to cyclically adjust the relative sizes of areas 304 and305. The picture can be stretched proportionally so that its Ycoordinate, shown as 306, fits properly within the screen. The pictureis then moved back and forth to reduce the asymmetry in the screen burnin process. Preferably, moving occurs in a way which will not becomedisconcerting to the user. For example, the picture may be moved veryslowly, or moved to a different location only in between scenes, inbetween shows, or in between watching sessions.

This will still mean that the center portion of the screen will receivedisplay at all times. The total brightness received by the edge portionsof the screen will be more even. However, the center portion will alwaysbe displaying video, and hence will still receive more total brightness.

Accordingly, another embodiment maintains a table of an amount ofbrightness received by each portion of the screen over time. Basically,the screen can be divided into slices in the y direction, shown as 309.Each slice, which may be for example 1/20th of the screen or 1/10th forthe screen, is maintained as a bucket representing the total amount ofbrightness that has been displayed by that bucket. A number isassociated with the bucket, and incremented each time the slice receivesa specified amount of brightness.

In another embodiment, the actual average brightness display to thescreen is also monitored. When that average brightness integrated overtime exceeds a specified amount, the brightness bucket is incremented.

Based on the brightness bucket, compensation for brightness can becarried out. Different brightness compensations which attempt to makesure that the screen is evenly used may include the following. In oneaspect, the edges of the screen may be slightly brightened as comparedwith the center, during normal play. Preferably that brightening is byan amount which will not be noticed by the user or negligibly noticed bythe user. For example, it is believed that a 20% brightness increasemight not be noticed as undesirable by the user. Another brightnesscompensation alternative is to provide picture to the edge portionswhich require compensation, during times in the television is not inuse. For example, the user can be informed of the fact that a brightnesscompensation routine needs to be carried out, and asked for a time whenthey will not be in the room, during which the compensation can becarried out. For example, during the day when the television is notbeing used, most users will probably not find it objectionable todisplay white bands on the sides in order to compensate in this way.Another aspect provides a motion or heat sensor in the room, to sensewhen the room is empty of people, using conventional motion sensortechniques. The compensation can be carried out when the room does nothave people therein. The compensation carried out during this time canbe of any desired type, since the room will presumably not be observedby any people during this time.

One alternative operation may display closed captions in the side bars,instead of over the picture as conventional. This may be combined withthe picture moving embodiment and/or the average brightness monitoringembodiments, as disclosed above.

FIG. 3B shows a first of the correlated interpret enhance routines inwhich edge portions 320 are compensated using the content of the pictureportion 321. First, the portion at the edge 322, 323 of the pictureportion 321 is analyzed. This may be the edge 20%, edge 10% or even theedge 5% of the content. Alternatively, this may be the entire pixelcontent or may be only a few pixels. However analyzed, this edge portion322 is used to form a supplemental video portion which will be used atthe edge portion 322 to match to the existing video image.

One aspect may match the median color. The median color here is definedas the color pixel which is found most often in a specified portion.Another aspect may include matching the average brightness, that is theaverage luminance of the areas. This area 322 may be matched, as shown,in different bucket portions. In one aspect, a bucket may be a squareneighborhood, where the width of the areas 322 also defines its height,shown as 324. However, the buckets can be of any shape; the matching canbe carried out over the entire y direction, or may be carried out overdifferent portions at different times.

FIGS. 4A-4D shows the operation of the enhancing and interpolating theimage to form edge portions. FIG. 4A, the first bucket 324 is evaluated,as described above, interpreted to determine the second bucket 402 whichhas similar image characteristics to the first bucket.

FIG. 4B describes a database approach. According to FIG. 4B, the systemmaintains a database of usually used television program textures. Thetexture of the area 324 is found at 405. That texture is matched to oneof the commonly-used textures at 408. Once that texture is found, thattexture is applied to the area 402 at 411. The texture may be used alongwith average color, median color as described above, and/or averagebrightness taken from the bucket 324. Preferably however, the mediancolor of the bucket 324 and the average brightness of the bucket 324 isused to set the same parameters in area 402.

FIG. 4C represents a system of extracting the actual texture, that is apattern within the image defined by the area 400.

FIG. 4C shows analyzing a neighborhood 324, and individual pixel partswithin that neighborhood. For example, each block of 4×4 pixels withinthe area 324 may be characterized. Each 4×4 neighborhood 324 is averagedat 420. Each 4×4 neighborhood is then classified for luminance, e.g.,between the values zero and 7 at 422, that is for example zero beingleast bright and seven being the most bright. This classification simplycoarsely classifies each pixel luminance. The values are used to formthat texture, with each bit portion in the texture being represented bya value between zero and seven representing an average luminance. Thattexture is then used as the interpolated texture 424, either exactly asit is, or after left to right inversion.

The above has described substantially simplifying the amount of datawhich is stored for the texture, both by simplifying that number ofluminance values that are stored, and simplifying the total number ofpixel values which are stored. However, it should be understood that theraw data can be obtained without simplification. The simplification,however, may allow the processing to the carried out more effectively.

FIG. 4D depicts finding basic shapes within the portion 400. Here, thevideo 444 includes a line in area 450, and a geometrical area 460. Inthis embodiment, the processing finds certain basic shapes using a shaperecognition algorithm as known in the art. The interpolation thencomputes the basic shape beyond the edge of the video; for example, thebasic shape 450 is completed as shape envelope 451. The basic shape 460may simply be mirrored to form the shape 462 as a mirrored portion ofthe shape 460. When a known shape is found at the edge, that known shapeis simply continued; when an unknown non regular or non-known shape isfound, that shape may also be mirrored. Of course, other more advancedshape matching algorithms can also be used in an analogous way.

FIGS. 5A-5C represent an embodiment where the extra information is notcalculated, but is rather obtained. In FIG. 5A, a database 501 of“additional information” represented in FIG. 4A as area 402, ismaintained. FIG. 5A shows this database as being coupled to processor110, which coupling can be a wired connection, or wireless, or over thechannel that carries the video. Database 500 can be maintained at acentral location, or within the television itself. That informationstates that given a basic portion of x shown as 501, you are likely tohave an extended portion of 502.

Many of the programs which are broadcast or available in 4:3 broadcastresolution are actually programs which have more information associatedwith them, but which have been truncated to fit within the NTSC standardbroadcast. For example, many movies and other shows are “edited fortelevision”, meaning that the enhanced aspect ratio portions have beenremoved. The database may represent how the average editing of this typeoccurs, or may be a database of precompiled information of the typedescribed above in FIG. 4A-4D.

FIG. 5B shows a flowchart of storing and reconstituting the actualinformation that is removed during editing. That additional information,removed when the show has been edited for television, is sent to thetelevision in a separate way. In the FIG. 5 B embodiment, for example,each show is assigned a unique identifier at 510. The widescreeninformation is stored separately from the narrow (edited) screeninformation at 512. The user (or television automatically) can requestat 514 that additional information which is sent over the cable channelthat is the communication channel or sent over a network. In this way,the actual additional information can be sent separately from thetelevision show. This can be done as a for pay arrangement, for example;the television stations can send the additional information on a per usebasis, or including commercials therein.

FIG. 5C shows yet another embodiment in which the widescreen informationis sent totally separately from the NTSC standard information. Thewidescreen information may be sent over a separate channel over theInternet or over a broadcast channel of different type. The widescreeninformation can be sent, for example, as Digital compressed video. TheDigital compressed video, for example in MPEG4 format, is then decodedby the television and in is displayed as the additional information.FIG. 5C shows the NTSC standard information 520 being sent separatelyfrom the “extra” information 522 used to produce the edge portions 304,305.

In an alternative embodiment, the edge portions, which would otherwisebe blank, may be used for additional textual information. For example,they can be used for closed captions, foreign translations intoalternative languages, or other notes or supplemental information. Itmay be advantageous when the extra portions are being used for textualannotations of this type, for the video to the pinned against either theleft or the right side of the screen. This may be used with a variant ofthe FIG. 3A embodiment, in which the video is first displayed against aleft side of the screen, and subsequently displayed against the rightside of the screen.

The above has described some basic techniques, but it should beunderstood that other modifications in the above are possible. Oneprimary modification which is intended is that this system be usablewith other forms of video distribution, such as video over IP, and videoover any other channel.

Another aspect is explained with reference to FIGS. 6A-6C. One problemwith stretching the aspect ratio is that certain things will lookunnatural when stretched. A person who is stretched in the verticaldirection obtains a totally different look, and often has a shape thatlooks unnatural. According to this embodiment, different portions of thescreen are analyzed, and it is determined whether these portions of thescreen are other types which can be stretched horizontally withoutdistorting. For example, a person cannot be stretched significantly inthe horizontal direction, without being distorted by the stretchingoperation. The adaptive stretching classifies the objects about whetherthey can be stretched or not.

FIG. 6A illustrates an exemplary image 600 which is to be displayed onthe screen of the television. While this image is depicted as being animage format, it should be understood that the image could bemanipulated by the processor while the image is still present as adigital signal. Different portions within the image are classified. Forexample, the image shown in FIG. 6A has text portions 605, anotherportion showing a cat 610, and yet another portions 615 showing a stool.Each of these objects 605, 610, 615 are classified. A decision is madefor each object individually as to whether the object will lookdistorted when stretched horizontally.

The screen is then divided into vertical sections, with certain verticalsections such as 620 having no objects therein, and therefore presumablybeing only background. Other vertical sections such as 622 include textonly. Still another vertical section 624 includes an animate object and626 includes an inanimate object.

The vertical sections are classified as to whether they can be stretchedwithout distortion or not. The slices such as 620 and 623 which includeonly background or textures therein can certainly be stretched. Portionswith text only can be stretched such as 622. In general, inanimateobjects such as present in slice 626 can be stretched, while animateobjects such as present in slice 624 cannot be stretched. The sliceswhich can be stretched are stretched by the desired amount forming awidened aspect ratio in which the slice 624 is maintained as notstretched, but slices such as 626 are stretched. The slices such as 623which include text are also stretched, as is the slice 622 whichincludes text.

FIG. 6B shows the result of the adaptive stretching in which certainitems, here are the ones with inanimate objects and text, are stretched(in the direction parallel to the horizontal plane), but other items,here the ones with animate objects are not stretched.

This may work fine in certain circumstances, but may distort theperspective of the scene. For example, it can be seen in FIG. 6A thatthe cat in 610 is very close to the text 605. However, in FIG. 6B, thecat is much further from the text 622. This may create distortions inthe field of the picture. For example, if the cat starts walking towardsthe text, the successive frames will be compensated in a similar way tothat discussed above, making the cat's walking seen unnaturally fast.FIG. 6C illustrates an embodiment with object based stretching. In FIG.6C, each slice is stretched by the same percentage stretch. Therefore,all of the slices become wider proportionally. However, rather thanchanging the aspect ratio of the unstretchable objects, the otherstretchable objects are adjusted not only in the vertical direction butalso in the horizontal direction. Therefore, the cat in 610 is stretchedin both vertical and horizontal directions so that its vertical tohorizontal ratio is maintained constant. Slice 624 is still stretched,but is stretched without distorting the animate object 610. In contrast,the other objects, such as the object 615 is stretched vertically onlysince the vertical stretching will not affect these objects. In summarythen, the embodiment of FIG. 6C classifies each object as to whether itcan be stretched or not, forms and vertical strips with each verticalstrip encompassing and object, and determines the way in which thevertical strip should be stretched based on the object within thevertical stretch.

Multiple objects may be within a single vertical strip, and thesemultiple objects may be handled differently. For example, a strip whichincludes both animate and inanimate objects would not be stretched inthe FIG. 6B embodiment, but would be partly stretched in the FIG. 6Cembodiment so that only the objects 610 would be stretched horizontally,while other objects which are inanimate would be stretched onlyvertically and have their length to width ratios altered appropriately.

Although only a few embodiments have been disclosed in detail above,other modifications are possible, and this disclosure is intended tocover all such modifications, and most particularly, any modificationwhich might be predictable to a person having ordinary skill in the art.For example, while the above has described a processor operatingaccording to a flowchart, it should be understood that this can be doneby a DSP, or by FPGAs, or any other structure that can processinformation. This can also be done by a “shader” in the video processinghardware.

Also, only those claims which use the words “means for” are intended tobe interpreted under 35 USC 112, sixth paragraph. Moreover, nolimitations from the specification are intended to be read into anyclaims, unless those limitations are expressly included in the claims.

1. A method comprising: obtaining video information having a first ratioof length to width; and automatically determining additional videoinformation for a wider width display.
 2. A method as in claim 1,wherein said automatically determining comprises processing at least anedge portion of the video information, and automatically calculating anadditional portion that is correlated with said edge portion.
 3. Amethod as in claim 2, wherein said additional portion is calculatedbased on a texture of said at least an edge portion.
 4. A method as inclaim 2, wherein said additional portion is calculated based on a colorof at least an edge portion.
 5. A method as in claim 2, wherein saidadditional portion is calculated based on an average brightness of saidat least an edge portion.
 6. A method as in claim 1, wherein saidadditional portion is calculated based on a shape of objects within saidat least an edge portion.
 7. A method as in claim 6, wherein saidautomatically determining comprises determining objects in said edgeportion, determining shapes which represent likely continuations of saidobjects, and producing said additional video information which includesinformation indicative of a continuation of said shapes.
 8. A method asin claim 1, wherein said automatically determining comprises processingsaid video information to determine at least one characteristic of saidvideo information, and determining said additional portion from adatabase.
 9. A method as in claim 8, wherein said at least onecharacteristic is a unique identifier indicative of a video program. 10.A method as in claim 8, wherein said at least one characteristic is atexture of the video program.
 11. A method as in claim 1, wherein saidautomatically determining comprises obtaining additional videoinformation over a channel, separate from said video information.
 12. Amethod as in claim 1, wherein said automatically determining comprisesclassifying objects within the video information, and stretching some,but not all of the video information horizontally by a specified amountbased on said classifying.
 13. A method as in claim 12, wherein saidclassifying comprises determining if the object can be stretched onedimensionally without distorting its look.
 14. A method as in claim 12,wherein said classifying comprises determining if the object can bestretched one dimensionally without distorting its look, stretching theobject in a single dimension if it can be stretched, and stretching atleast one object in two dimensions while maintaining an aspect ratio ofthe object, if the object cannot be one dimensionally stretched.
 15. Amethod as in claim 12, further comprising stretching other parts of thevideo information horizontally by a second specified amount based onsaid classifying.
 16. A method as in claim 1, further comprisingdisplaying said additional video information along with said videoinformation, on a video screen.
 17. An apparatus, comprising: aprocessing element, which receives video information as an inputthereto, said video information having a first ratio between length andwidth of the video information, and said processing element operating toautomatically determine additional video information for display on adisplay with second, wider ratio between length and width.
 18. Anapparatus as in claim 17, wherein said processing element processes atleast an edge portion of the video information, and automaticallycalculates said additional video information based on said at least edgeportion, which additional video information is correlated with said atleast edge portion.
 19. An apparatus as in claim 18, wherein saidprocessing element determines a texture of said at least edge portion,and calculates said additional video information having a texturerelated to said calculated texture.
 20. An apparatus as in claim 18,wherein said processing element determines a color of said at least edgeportion, and calculates said additional video information having a colorrelated to said calculated color.
 21. An apparatus as in claim 18,wherein said processing element determines a brightness of said at leastedge portion, and calculates said additional video information having abrightness related to said calculated brightness.
 22. An apparatus as inclaim 18, wherein said processing element automatically recognizesshapes within said video information, and calculates a continuation ofsaid shapes in said additional video information.
 23. An apparatus as inclaim 17, further comprising a database of additional video information,and wherein said processing element determines at least onecharacteristic of said video information, and automatically determinessaid additional portion from said database.
 24. An apparatus as in claim23, wherein said database of additional video information storesadditional information which has been removed from video programs byediting, along with identifiers of said video programs, and saidprocessing element determines an identifier of the video program anduses said identifier to obtain said additional information from saiddatabase.
 25. An apparatus as in claim 17, wherein said processingelement operates to classify objects within the video information todetermine information indicative of whether the objects can be stretchedone dimensionally.
 26. An apparatus as in claim 25, wherein saidprocessing element stretches vertical portions of said video informationbased on objects classified within said vertical portions.
 27. Anapparatus as in claim 26, wherein said processing element stretches somevertical portions more than it stretches other vertical portions.
 28. Anapparatus as in claim 17, further comprising a video processing partwithin said processing element, which outputs video information havingsaid second wider ratio between length and width, based on said videoinformation, and said additional video information.
 29. A method,comprising: receiving video information; processing said videoinformation to interpolate additional video information intended to formadditional portions for a wider aspect ratio video information; andproducing a signal indicative of said video information and saidadditional video information for display on a display element havingsaid wider aspect ratio.
 30. A method as in claim 29, wherein saidadditional video information includes information which is matched toedges of said video information.
 31. A method as in claim 29, whereinsaid additional video information includes stretched vertical portionsof said video information.